This invention is generally directed to a module transporter. More specifically, the invention is directed to a transporter for use in moving large loads, such as portions of ships, whose height may be regulated and which is powered by a motivator with a small turning radius.
In order to transport large loads, such as the bow, deckhouse or other portions of ships, from the manufacturing facility to the erection site for their ultimate connection, a large frame mounted to a series of wheeled carts has been used. Each wheeled cart typically included a set of steerable wheels, as shown in FIG. 1. Forward and rearward pairs of wheeled carts are connected by chain falls or "tug-its" to accomplish manual steering. The entire frame can be pushed forward using a separately powered vehicle.
Such conventional transporter frames, however, do not permit the operator to raise or lower the load during transport. This is often necessary due to uneven terrain. Conventional transporters are also characteristically time-consuming to set up and operate.
Movable hydraulic dollies have also been used. While such dollies permit the load to be raised or lowered while stationary, they are not easily positioned, and require time to do so. Nonmovable jack dolleys have also been used to support large loads in elevated positions. Finally, while some large loading dollies have been capable of both horizontal and vertical positioning, these dollies are not easily steered. Also, vertical or horizontal movement is not easily accomplished with such devices, and cannot be performed in a relatively short amount of time.
To overcome some of the deficiencies in the prior art, the assignee of the present invention developed a "tuning fork" transporter frame design, shown in FIGS. 2A and 2B. This transporter frame consists of two parallel, wheeled "forks" joined by a forwardly positioned yoke. The yoke is pivotally connected to a base portion of the front of a conventional fork lift, as shown. The fork lift raises and lowers the yoke. Rear fork portions are each mounted to a pair of wheels on a cart, and a hydraulic cylinder linkage is associated with each cart. The cylinder linkage, connected in parallel to a common hydraulic pump, permits the rear fork portions to be jointly raised or lowered. However, each of the two rear fork lift points cannot be independently raised and lowered.
While the tuning fork transporter design is an improvement over the prior art, there are still disadvantages associated with it. For example, it requires a relatively large turning radius. Also, a three-lift-point design in which each lift point can be independently raised and lowered would provide the transporter with enhanced maneuverability. Further, the tuning fork design cannot be used with loads of more than about 20 tons, due to limitations in the fork-lift lifting and pulling abilities, and due to strength limitations in the "tuning fork" structure.